2016-03-25.md

Subteam report: libs 2016-03-25

Highlights

Several RFCs enter their final comment period this week:

• FCP PR #1398: Allocators, take III
  • Proposes a comprehensive API for describing and using allocators, with the intent that types like Vec and HashMap can ultimately support custom allocators.
• FCP PR #1529: rfc 1291: Add libutil to scope of libc crate on Linux
• FCP PR #1552: Add a contains method to VecDeque and LinkedList

As usual, we covered several PRs that needed team decisions:

• Decreasing code bloat when deriving Clone for Copy data
  • We want to do this, but had some reservations about the initially-proposed approach.
• Changing AtomicBool size to 1 byte
  • We want to reach a decision here while resolving open RFCs on the topic.
• Placement for Vec
  • We want to add these APIs, but are wary of doing so in an ad hoc way without any conventions (and thereby de facto stabilizing poor conventions); blocked on a quick conventions RFC.
• Heap allocation guarantee
  • We are fine with making this promise, but would like to avoid a lot of ad hoc promise-making along these lines, in favor of a more comprehensive look at representation promises.
• Add augmented assignment to time times
  • Merged

We did some maintenance on the nursery:

• Making progress on rustc-serialize without breakage
• We need to consolidate the time libraries in the ecosystem, and in particular make the external time libraries compatible with the new std::time types. Ideally, this would happen by deprecating the time crate in favor of chrono, and making chrono more std-compatible. The libs team is working with the relevant authors to make progress here.
• Dealing with libc/std::os::raw types and their interaction.
  • Not fully resolved -- ongoing discussion is here.

Dashboard

High priority issues

Issues needing a decision

RFC phase

• FCP PR #1398: Allocators, take III
• FCP PR #1529: rfc 1291: Add libutil to scope of libc crate on Linux
• FCP PR #1552: Add a contains method to VecDeque and LinkedList
• PR #1218: RFC: Checked integer conversions
• PR #1309: OS string string-like interface
• PR #1325: Add panic-safe slicing methods
• PR #1353: Add retain_mut to Vec and VecDeque
• PR #1379: Change thread local variables to only accept async-signal-safe types.
• PR #1480: RFC proposal for thread affinity
• PR #1502: libstd::sys, the great libstd refactor
• PR #1505: Add a generic Atomic type
• PR #1521: Copy clone semantics
• PR #1533: Keyless Entry
• PR #1534: RFC: Saturating and checking integer wrapper types
• PR #1542: Add TryFrom and TryInto traits
• PR #1543: Add more integer atomic types
• PR #1547: as_millis function on std::time::Duration

Implementation phase

• Issue #5016: implement "dynamic drop" semantics using flags on the stack rather than zeroing
• Issue #19986: Tracking issue for collections reform part 2 (RFC 509)
• Issue #32310: Tracking issue for {Vec,String}::splice
• Issue #32311: Tracking issue for Range*::contains
• Issue #32313: Tracking issue for Ipv6Addr octet methods

Stabilization phase

• FCP Issue #27719: Tracking issue for recover stabilization
• FCP Issue #27751: Tracking issue for raw stabilization
• FCP Issue #27754: Tracking issue for str_char stabilization
• FCP Issue #27780: Tracking issue for <*mut T, *const T>::{as_ref, as_mut_ref}
• FCP Issue #27784: Tracking issue for char encoding methods
• FCP Issue #27809: Tracking issue for make_ascii_{upper,lower}case
• FCP Issue #27811: Tracking issue for CommandExt::session_leader
• FCP Issue #27830: Tracking issue for UTF-16 decoding iterators
• FCP Issue #28050: Set recovery methods
• FCP Issue #29453: Add Capacity/length methods for OsString
• FCP Issue #29791: Tracking issue for getting pthread_t from JoinHandle
• FCP Issue #29935: Tracking issue for #[deprecated]
• FCP Issue #30014: Tracking issue for OpenOptions expansion
• FCP Issue #30752: Tracking issue for panic::propagate
• FCP Issue #31262: HashMap and HashSet should provide a getter for their hashers
• FCP Issue #31398: Tracking issue for CommandExt::{exec, before_exec}
• FCP Issue #31405: Tracking issue for file_try_clone
• FCP Issue #31572: Tracking issue for SocketAddr setters
• FCP Issue #31755: Tracking issue for <[T]>::copy_from_slice
• FCP Issue #31756: Tracking issue for ptr::{read,write}_volatile
• Issue #5016: implement "dynamic drop" semantics using flags on the stack rather than zeroing
• Issue #24263: discriminant_value intrinsic -- tracking issue for 639
• Issue #27389: Tracking issue for changing the global, default allocator (RFC 1183)
• Issue #27700: Tracking issue for allocation APIs
• Issue #27703: Tracking issue for stabilizing randomness
• Issue #27705: Tracking issue for DNS in std::net
• Issue #27708: Tracking issue for as_unsafe_cell stabilization
• Issue #27709: Tracking issue for Ipv{4,6}Addr convenience methods
• Issue #27716: Tracking issue for thread_local_state stabilization
• Issue #27717: Tracking issue for static synchronization primitives
• Issue #27720: Tracking issue for OpenOptionsExt on Windows
• Issue #27721: Tracking issue for string patterns
• Issue #27726: Tracking issue for access to Formatter flags/options
• Issue #27730: Tracking issue for NonZero/Unique/Shared stabilization
• Issue #27731: Tracking issue for SIMD support
• Issue #27732: Tracking issue for DST coercions (coerce_unsized, unsize) stabilization
• Issue #27733: Tracking issue for borrow_state stabilization
• Issue #27739: Tracking issue for Zero/One/iter_arith stabilization
• Issue #27741: Tracking issue for step_by stabilization
• Issue #27745: Tracking issue for type_id stabilization
• Issue #27747: Tracking issue for slice_concat_ext stabilization
• Issue #27749: Tracking issue for Reflect stabilization
• Issue #27752: Tracking issue for float_extras stabilization
• Issue #27778: Tracking issue for core::array
• Issue #27779: Tracking issue for placement new
• Issue #27783: Tracking issue for location of facade crates
• Issue #27787: Tracking issue for sorted collection ranges
• Issue #27788: Tracking issue for VecDeque Extras
• Issue #27791: Tracking issue for str escaping
• Issue #27794: Tracking issue for extra linked list methods
• Issue #27800: Tracking issue for channel selection
• Issue #27802: Tracking issue for Read::chars
• Issue #27812: Tracking issue for crates that are compiler dependencies
• Issue #28147: Tracking issue for BinaryHeap::{push_pop, replace}
• Issue #28237: Tracking issue for ... inclusive ranges (RFC #1192)
• Issue #28356: Tracking issue for Arc/Rc extras
• Issue #28796: Tracking issue for FnBox()
• Issue #29553: Tracking issue for #[bench] and benchmarking support
• Issue #29625: Tracking issue for Fn traits (unboxed_closures feature)
• Issue #30172: Implement placement-in protocol for relevant data structures
• Issue #30425: No way to construct std::rc::Weak without a strong reference
• Issue #30449: Custom panic handlers in the standard library
• Issue #30877: Tracking issue for RangeArgument
• Issue #31190: Tracking issue for CStr::from_bytes_with_nul
• Issue #31399: Tracking issue for SystemTime accessors from fs::Metadata
• Issue #31767: Tracking issue for compare_exchange
• Issue #32110: Tracking issue for libcore prelude traits
• Issue #32111: Tracking issue for the Peekable::is_empty function
• Issue #32281: Add methods exposing keys of BTreeMap and HashMap entries
• Issue #32312: Tracking issue for Unix Sockets in the standard library